Help!! Ariston microsystem 21 external voltage is too low!!

[jackkim]

Hi, I am new on here and hope someone can help.

I have the Ariston microsystem 21 boiler and it supposed be support 240v AC to the junction which connected to water tank, 2 pumps and timer as attached diagram but it supported only 6v AC somehow.

The honeywell ST6400C wasn't display anything because rack of power I think.

Shall I change the PCBs? It has 2 PCBs, one has LEDs with switches and the other one has many small parts on it.

Pleeease kindly check the electrical diagram which I attached and tell me what shall I do.

Many Thanks!!

Jack

 

[picasso]

Have you checked the fuse on the board and the fuse in the spur ?

 

[matt1e]

Pleeease kindly check the electrical diagram which I attached and tell me what shall I do.

Many Thanks!!

Jack

well I would check it if I could see it jack

Edit ok I found it I'll post the link for you

Electrical diagram 1

• jackkim
• 19 Dec 2010
• 1

Electrical diagram 2

• jackkim
• 19 Dec 2010
• 1

Have you checked the fuse on the board and the fuse in the spur ?

err as picasso has stated would be a good start

Matt

 

[bengasman]

... it supposed be support 240v AC to the junction which connected to water tank, 2 pumps and timer as attached diagram but it supported only 6v AC somehow.

Shall I change the PCBs?

I could be wrong, but I think the 230V is supposed to feed the pcb, the pcb does not provide the required 230V to feed the boiler.

Apart from that, if you find 6V somewhere, your earth is probably not 100% either.

 

[jackkim]

Have you checked the fuse on the board and the fuse in the spur ?

Thanks for your quick reply.
The fuse is fine.

 

[jackkim]

Pleeease kindly check the electrical diagram which I attached and tell me what shall I do.

Many Thanks!!

Jack

well I would check it if I could see it jack

Edit ok I found it I'll post the link for you

Electrical diagram 1

• jackkim
• 19 Dec 2010
• 1

Electrical diagram 2

• jackkim
• 19 Dec 2010
• 1

Have you checked the fuse on the board and the fuse in the spur ?

err as picasso has stated would be a good start

Matt

Thanks Matt!!
Now I can see my photos.

 

[jackkim]

... it supposed be support 240v AC to the junction which connected to water tank, 2 pumps and timer as attached diagram but it supported only 6v AC somehow.

Shall I change the PCBs?

I could be wrong, but I think the 230V is supposed to feed the pcb, the pcb does not provide the required 230V to feed the boiler.

Apart from that, if you find 6V somewhere, your earth is probably not 100% either.

Thanks for your reply.

Yes, the 230v is supposed to feed the pcb and coming out from pcb and supposed to feed the terminal block which connected to others. The pumps and timer needs 230v but the power should be supplied by boiler (actually from pcb's external terminal, N and 1) as shown in the electrical diagram. I couldn't find any other power input to terminal block except from boiler.

I though something wrong with one or both of pcbs and supplied only 6v instead of 230v at external output terminal as I marked on a diagram.

Oh, I checked my earth many times by the way.
Actually, I changed one of pcb which has LEDs and switches but same.

Shall I change another one(999498, CBM2 AT-MI2X)?

It is such pain especailly in cold weather, help!!

Jack

 

[matt1e]

I could be wrong, but I think the 230V is supposed to feed the pcb, the pcb does not provide the required 230V to feed the boiler.

the mains supply to the boiler is via a flex to the left of the The terminals he has highlighted
terminal one is indeed a live feed from the boiler to external controls

Have you checked the fuse on the board and the fuse in the spur ?

Thanks for your quick reply.
The fuse is fine.

there are two to check one in the spur and a 2 amp one one the conections board

jack you dont say if you have any power to the boiler
is the mains and central heating led on?
if so also check system pressure is not low as there is a pressure switch connected in series with terminal 1

Matt

 

[bengasman]

...Oh, I checked my earth many times by the way.

And???
Did you only test at the boiler or also at the cut out?
What was the impedance?

Shall I change another one(999498, CBM2 AT-MI2X)?

Changing parts at random hoping it will solve the problem is a bad and often expensive strategy.
What you should do, is find the fault. Failing that, get a pro in.

 

[jackkim]

Thank you very much, Matt!!

I checked system pressure and I found it was low!
Once put some water in order to make the pressure higher and... it WORKS now!!!
Such simple check point but it was greatest Christmas gift for me, Matt!!
Thank you so much once again and I wish you merry Christmas!!

Jack

I could be wrong, but I think the 230V is supposed to feed the pcb, the pcb does not provide the required 230V to feed the boiler.

the mains supply to the boiler is via a flex to the left of the The terminals he has highlighted
terminal one is indeed a live feed from the boiler to external controls

Have you checked the fuse on the board and the fuse in the spur ?

Thanks for your quick reply.
The fuse is fine.

there are two to check one in the spur and a 2 amp one one the conections board

jack you dont say if you have any power to the boiler
is the mains and central heating led on?
if so also check system pressure is not low as there is a pressure switch connected in series with terminal 1

Matt